PHILADELPHIA — The 76ers are in a tough spot. On paper, they’ll have a hard time winning consistently with Joel Embiid sidelined for an extended time following surgery on the lateral meniscus in his left knee. Monday’s 118-102 loss to the Dallas Mavericks at the Wells Fargo Center was an example of the Sixers playing hard, but ultimately being doomed by a lack of bodies. The Mavericks (27-23) opened the fourth quarter on a 15-3 run to take a commanding 92-77 lead and never looked back. In addition to missing Embiid, the Sixers (30-19) were without starters De’Anthony Melton and Nico Batum. The…